Surface testing and recording machine



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SURFACE TESTING AND RECORDING MACHINE Filed Jan. 15, 1940 9 Sheets-Sheet 9 4 [5.50. 336 E i 0 865 I 865 [I E Patented Oct. 28, 1941 OFFICE SURFACE TESTING AND RECORDING MACHINE Ougljesa J. loupitch, Chicago, 111., assignor to Illinois Tool Worlrs,.Chicago, 111., a corporation of Illinois Application January 15, 1940, Serial No. 313,888

27 Claims.

invention relates to ,a surface tester and recorder. It is an object of this invention to provide a compact, inexpensive, eificient and highly sensitive surface tester and universal recorder providing means by which the data taken may be recorded at a point remote from the testing machine.

Another object of the invention is to provide a universal recorder and attachments for standard testing machines such as machines for testing gear surfaces or tooth profiles by which a single recorder maybe used with any number of standard testing machines equipped with these attachments.

A further object of the invention is to provide in a tester and recorder of the above stated chara'cter means for electrically controlling the feeder movement of a record sheet'so that the record sheet is moved in synchronism with a testing instrumentality and wherein means are provided for controlling the direction of movement of the record sheet so that the record sheet may be moved in one direction even though the direction of movement or action of the testing instrumentality be reversed.

Applican'ts invention further contemplates the provision of recorder control attachments which may be used with'a large number of standard surface testing machines difiering radically in construction.

A further object of the invention is to provide an electro-optical testing instrumentality responsive to deviations in the surface of an object from a desired shape in combination with electrical means responsiveto a relative movement between the object and the testing instrumentality for operating a record sheet in synchronism with such relative movement, the record sheet being marked or inscribed by means controlled by the testing instrumentality.

A more specific object of the invention is to provide an electro-optical surface testing instrumentality capable of universal adjustment to test surfaces of any desired configuration.

Other objects and advantages will be apparent from the following description when taken in connection with the accompanying drawings wherein:

Fig. 1 is a view in perspective of an involute testing machine and recorder and is illustrative of one embodiment of the invention;

- Fig. 2 is a fragmentary view in elevation illustrating the control panel of the recorder;

Fig.3 is a view in vertical section taken substantially along the line 3-3 of Fig. 1;

Fig. 4 is a fragmentary vertical section taken along the line 4-4 of Fig. 1;

Fig. 5 is a horizontal section taken along the line 5-5 of Fig. 4;

Fig. 6 is an enlarged fragmentary horizontal section taken along the line 66 of Fig. 4;

Fig. 6A is a view similar to Fig. 6, but with the parts in a different position of adjustment;

Fig. 7 is a fragmentary vertical section taken along the line 1-1 of Fig. 4;

Fig. 8 is a fragmentary vertical section taken along the line 8-8 of Fig. 4;

Fig. 9 is a perspective view of an adjusting cam forming part of the testing instrument;

Fig. 10 is a fragmentary horizontal section taken along the line Ill-l 0 of Fig. 8;

Fig. 11 is a fragmentary view in vertical section taken along the line Il-H of Fig. 4;

Fig. 12 is a fragmentary view in vertical section taken along the line l2-l2 of Fig. 4;

Fig. 13 is a view similar to Fig. 12, but showingthe parts in a different operative position;

Fig. 14 is a view in horizontal section taken substantially along the line l4-l4 of Fig. 16;

Fig. 15 is a fragmentary view in vertical section taken along the line l5-I5 of Fig. 1;

Fig. 16 is a view in vertical section taken substantially along the line Iii-f5 in Fig. 15;

Figs. 17, 18 and 19 are schematic drawings of electrical control circuits embodied in the invention;

Fig. 20 is a schematic drawing of a helical lead measuring machine equipped with the recorder control attachments forming part of the invention;

Fig. 21 is a view in vertical elevation taken from the left side of the-machine shown in Fig.

Fig. 22 is a fragmentary view in vertical section taken substantially along the line 22-22 of Fig. 20;

Fig. 23 is a diagrammatic illustration of a helical gear to aid in understanding of the operface may be tested by the machine of Figs. 24 to 26;

Fig. 30 is an illustrative view of a record sheet provided by the recorder of the invention.

Referring now to the drawings more in detail, it will be seen that the invention includes an electro-optical surface measuring or testing instrumentality 2 (Figs. 1 and 2 to 13), a position responsive control means 4 (Figs. 3 and 17), and a paper feed drive unit 6 (Figs. 1 and 1-4 to 16) for an electric recorder 8, and an electric control unit I0, including connections for maintaining the position responsive means and the paper feed drive unit in synchronism. The electro optical testing instrumentality 2 and the position responsive means 4 are formed as attachments'of universal application to standard surface testing machines such as machines for testing gears.

In Figs. 1 to 10 the invention is shown as associated with a standard involute measuring or testing machine I2 which comprises a suitable base I4. Mounted upon the upper portion of the base I4 is a slide frame I6 slidable upon horizontal ways or tracks I8 provided along the upper edge of the base I4. The frame I6 is formed with a depending section 28 (Fig. 3) in which is journalled a sleeve 22, thesleeve 22 being retained by when clamping the disk on the spindle 32 also couples the spindle and cylinder for simultaneous rotation and hence the rotation of the base disk is imparted to the gear to be tested through the nut 42-, the spindle 32, the lever 64, the post 68, and the pin I8. v

The testing instrumentality 2 is supported upon a frame I4 which is slidably mounted upon the front end of the base I4. The frame I4 is provided with a depending portion I6 to which is secured at its lower end a roller bearing I8 that frictionless bearings 24. A sleeve 26 is journalled in the bearings 24 and the sleeve 22. The sleeve 26 is provided at its upper end with an enlarged portion retaining the upper bearing 2'4 in position.

The sleeve 26 receives the tapered shank 38 of a spindle 32, which spindle is provided with an annular flange 34 that forms a support for a cylindrical member, ring or disk 36 which is of an external diameter equal to the diameter of the base circle of a gear 38 to be tested. The disk 36 constitutes in effect a base cylinder .for the gear to be tested and is detachably mounted on the spindle 32 so that it may be readily replaced by a similar disk of different size corresponding to a different size gear to be tested. The spindle 32 is threaded as at 48 adjacent itsupper end to receive a clamping nut 42 by which the disk is retained in position on the supporting flange 34.

- The spindle 32 terminates at its upper end in a conical work supporting center 44 which receives the lower end of the gear or work supporting spindle 41. The upper end of the spindle 46 is received by the center 48 (Fig. 1) which is carried by a tail stock 58, which tail stock includes a housing52 for the spindle that supports the center 48 and a pair of diverging arms..which terminate in sleeves 54. These sleeves 54 are slidable upon vertical posts or columns 56 and are adjustable vertically of the columns by a hand wheel 58 which controls a gear having meshing engagement'with the rack teeth 68 (Fig. 3) formed on one or both of the columns 56. The center 48 is adjustable with the spindle and relative to the housing 52 in a similar'man'ner by means of a hand wheel 62. The columns 56 are carried by the slide frame l6.

rolls along the fiat surface of a plate or bar 88 secured to the base I4. A similar roller bearing 82 is secured to the upper portion of the frame I4 and this hearing rolls along the forward surface of a bar 84 secured to the upper edge of the base I4. The frame I4 is additionally formed with a rearwardly extending, portion or section 86 overlying the bar 84 and extending downwardly behind the same. In its downward extension the section 86 carries a bar 88 in horizontal alignment with the bar 84 and between this bar 88 and the bar 84 are interposed a plurality of anti-friction ball bearings 98.

A bar 92 is secured to the section 86 of the frame I4'and is provided with a friction surface to engage the peripheral surface of the base disc or cylinder 36 so that when the bar 92 is moved horizontallywith the frame I4 rotation is imparted to the base disc or cylinder 36. The frame I4 is moved horizontally by means of a hand wheel 94 (Fig. 1) which controls a system of gears (not shown), the end gear of which meshes with the rack teeth 96 (Fig. 3) provided along the underside of the stationary bar 84.

An auxiliary frame 98 is mounted on the frame I4 and is slidable in ways formed on the downward extension .16 of the frame I4. Vertical adjustment of the auxiliary frame 98 is accomplished by the hand wheel I88 that controls the rotation of a gear I82 (Fig. 3) which in turn' meshes with a rack (not shown) secured to the The base disk or cylinder 36 is coupled to the gear 38 to be tested by a lever 64 which is detachably clamped to the spindle 32 and the arm of the sleeve is slotted as at 66 to receive a post or rod 68 that is clamped to the lever for adjustment along the slot 66. The post 68 supports for vvertical adjustment relative thereto a pin or rod I8 which is clamped on the post 68 by a set screw 12 carried by the supporting yoke for the pin I8. The pin I8 projects between the adjacent teeth of the gear 36 to be tested as shown in Fig. l.

The base disk or cylinder retaining nut 42 extension I6 of the frame I4. The testing instrumentality 2 is mounted upon this auxiliary frame or slide 98 as will subsequently be described.

In order to make a test, the slide frame I6 is first adjusted relative to the main base I4 and to the frame 14 to receive a disk or cylinder 36 of an external diameter equal to the base surface of the gear that is to be tested. This adjustment is accomplished by a feed screw I84 (Fig. 3) supported on the main base I4 and operated by a hand wheel I06, the feed screw engaging the threaded block I88 secured to the slide frame I6. The base disk or cylinder 36 of the appropriate size having been mounted on and clamped to the spindle 32, the slide frame I6 is adjusted to bring the disk into engagement with the frictionally effective driving bar 82.

A roller bearing III), carried by the slide bar II2 mounted on the slide frame I6, is urged by the spring II4 into engagement with the base disk or cylinder 36 at a point diametrically opposite to the point of engagement of the bar I88 with said disk. A gear or other work piece 38 having an involute tooth is mountedbetween the centers 44. and 48 and the two portions of the frame 14 are adjusted horizontally and vertically to position a testing instrumentality in proper position with respect to the involute surface to be tested or inspected.

An indicator finger H6 (Fig. 1) is" formed with 'furcated arms II8 (Fig. 3) which frictionally clamp in a peripheral recess in the upper portion of the sleeve 26. The frictional clamping of the indicator finger to the sleeve is sufficient to hold the finger securely against inadvertent movement and for indexing of the work, but is sufiiciently impositive to permit the finger to be shifted for purposes of manual adjustment. A suitable arcuate graduated scale I (Fig. l) is secured to the slide'frame I6 and cooperates with the finger to indicate the angular movement of the gear or work-piece during a testing operation. Before a test is started the finger or pointer H6 is moved to zero position, as indicated in Fig. 1. The gear may be indexed from tooth to tooth while the frame 98 is raised by hand, by manipulation of the finger H6 or any other suitable indexing means automatically and successively presenting the teeth to the testing instrumentality.

The testing instrumentality or device 2 is mounted upon the auxiliary frame or vertical s1ide'98. This instrumentality comprises a contactor I22 (Figs. 4 and 5) adjustably mounted in a block or tube I24 andretained in adjusted position therein by a set screw I26. The contactor I22 is adapted to engage the surface to be tested, viz., the involute tooth surfaces of the gear 38 at the .point of intersection of the base circle with the toothed surfaces and is adapted to control the deflection of a shiftable ray-controlling member or means I28. This ray-controlling member or means I28 comprises a lamp receiving housing I30 formed by oppositely inclined top and bottom walls I32 and I34, a forward wall I36 formed integrally with a mountingboss I38, and rearwardly diverging side walls l40 and I42. The lamp receiving housing I30 is open at its rear end and this end is arcuate in cross-section (as seen in Fig. 5), the side and bottom walls forming at this end of the housing a frame to receive an arcuate grid, grating screen, or the like I46. The screen I44 preferably comprises a sector of plate glass etched on its outer or convex surface with lines .001 of an inch in width spaced .001 of an inch apart. The screen, grid or grating I44 cooperates with a similar arcuate screen, grid or grating I46 mounted in a frame I48, the screen I46 being preferably formed with'a sector of plate glass etched on its inner or concave surface with lines of the same width and spacing as the lines 4 and 5) formed in the periphery of the mount ing ring i66. The upper part I16 of the split clamping ring I12 is releasably secured to the lower part I18 of the clamping ring as by means of screws 30.. The upper part I16 of the clamping ring I12 is provided with a radial opening I82 to permit a tool to be'inserted therethrough to adjust the center I58.

The lower part I18 of the clamping ring I12 is formed integrally with or secured to the horizontal arm I84 of a bracket secured to or formed integrally with the auxiliary frame or slide 88. The lower part of the clamping ring at its point of juncture with, or its connection to, the arm I84 is formed to provide an apertured boss I86 receiving a pair of aligned sleeves I88 and I90, in turn receiving the shank I92 of an adjusting screw I94. The sleeves I88 and I90 are slidably mounted in the boss I86 for relative movement toward and from each other, the sleeves at their inner ends having surfaces I96 which are longitudinally curved concentric to the axis of the ring I 66, as shown in Figure 11, but in transverse section are fiat, as shown in Figure 4, so as to engage the bottom surface of the groove I14 in the ring I66, thereby to prevent rotation of the sleeves in the boss I86, and to clamp the ring I66 against rotary movement. The shank I92 of the tube I24. The block or tube 128 is secured to the boss and the boss to the stud as by a screw or screws I52. An adjusting screw I58 is inserted into the inner end of the contactor I22 and engages the stud I50 or an inner wall surface of the block I20 to determine the radial-distance between the axis of the stud and the forward free edge or point of the contactor. A clamping nut E56 retains the adjusting screw I56 in adjusted position.

The stud I50 is mounted between adjustable centers I58 and I60. The centers I58 and I60 are preferably formed as integral parts of set screws I62 and I65 received in threaded, diametrically opposed, radial openings in a mounting ring I68 (Figs. 4, 5 and 11). Set screws I68 and I10 at right angles to the set screws I62 and I68 retain these set screws I62 and I65 in adjusted positions.

The mounting ring I66 is supported for radial adjustment in a split clamping ring I12 (Fig. 11) received in an annular groove or recess I14 (Figs.

adjusting pin I94 is threaded at its outer end, and mates with the internal threads of the sleeve I88, so that upon rotation of the adjusting screw this sleeve may be moved toward and from the ring I66. The head I94 of the adjusting screw engages the sleeve I90. Hence, upon rotation of the adjusting screw in one direction the sleeves I88 and I90 are moved toward each other and into clamping engagement with the ring I66, but

upon rotation in the opposite direction are loosened from this ring. Upon loosening of the clamping sleeves, the mounting ring may be rotatably adjusted relatively to the clamping ring I12, so that the contactor I22 may move along different inclined paths as the auxiliary frame or slide is moved vertically, whereby surfaces inclined at different angles to the rectilinear path of vertical movement of the slide 98 may be traversed by the contactor I22. It should be here noted that the common center of the arcuate Preferably the arcuate screens I44 and I46 are concentric to the axis of the pivot stud I50, so that as contactor I22 is deflected in response to the deviations of a tooth surface of'the gear 38 from the true involute curve, the screens will cooperate to vary the amount of light passed therethrough in strict proportionality to the movement of the contactor.

The screen IN is preferably mounted in the frame formed by the rear end of the lamp housing I30 by a dove-tail fit therein, and is preferably resiliently held by a spring catch,-or the like, I88, secured to a side wall of the lamp housing and passing through an opening in the frame-defining portion of the housing into engagement with an edge of the screen I44. Ac-

' cordingly, any loosening in the fit of the screen I44 is compensated by the spring MB.

A housing 200 is provided for enclosing the ray-controlling member or means ll28. This housing is preferably formed in two parts, to-wit: a forward part 202, and a rear part or cover 204, detachably secured to the forward part as by screws 206 carried by the rear part and received in the inwardly projecting threaded lugs 208 formed in the forward part 202. The screws 206 pass through larger openings 2I0 in the vertical side bars of the screen supporting frame I48 and through enlarged openings in the inwardly projecting lugs 2I2-of the forward part 202.

The frame I48 for the screen I46 is 'adjustably secured to the forward part 202 of the housing 200, as best shown in Figure 10. As illustrated in this figure, each side bar of the frame I48 is received between the spaced lugs 208 and 2I2, and each of these side bars carry adjacent its upper and lower ends a pin 2 I4, having a ground, preferably convex, forward face projecting forwardly from the frame bar and engaging the rear; face or faces of the lug or lugs 208. The rear faces of these lugs may be ground, if desired, so that in cooperation with the pins-2 I 4 the frame may be precisely positioned in a plane at right angles to the axis of the contactor I22. Set screws 2I6, carried by the lugs 2I2, engage the side bars of the frame I48 relatively adjacent the corners thereof to maintain the frame I48 and the screen I46 in adjusted position, in proper spaced relation to the screen I44. Set screws 2I8, carried by opposite walls of the forward part of the housing 200 engage opposite edges of the side bars of the frame I48 relatively adjacent to the four corners of the frame, and provide means for, in effect, angularly adjusting the frame and screen I46 precisely to'position the lines of the screen I46 parallel to the lines of the screen I44. Clamping nuts 220 maintain the set screws 2I8 in'adjusted position.

The walls of the forward part 202 of the housing 200 are inwardly offset as at 222 (see Figures 4 and 5), and an opposite pair of these offset wall portions are apertured to receive shouldered bushings 224 and 226 by whichthe housing is journalled on the centering pins I58 and I60. A spring washer 228, interposed between the bushing 224 and the inner surface of the ring I66, resiliently prevents movement of the housing axially of the centering pins.

A lamp, or ray source 230, is mounted upon the top wall of the housing 200, and extends into the lamp housing I30 through an enlarged opening in the top wall I32 of this lamp housing.

The lamp 230 isreceived within a socket 232, which preferably comprises an insulating cylinder holding an internally threaded metal socket (see Fig. 7), and having opposite contact pieces 234 adapted to engage terminal pins 236 carried by a ring 238 of insulating material secured to the top walls of the housing about an opening therein, through which opening the socket and lamp may be inserted into the housing 200 and the lamp positioned in the lamp housing I30. The top walls of the housing I30 and 200 are provided with aligned openings closed by transparent members or windows 240 and 242, which may be marked or etched with suitable indicia serving to indicate the relative positions of the screens I44 and I46. These transparent windows also provide means by which the operability of the lamp may be determined before any test is initiated.

An electro-optical cell 244 (Figs. 4 and 5) is mounted within the housing 200, and is secured in any convenient manner to the frame I48 for the screen I46, or to the rearpart of cover 204 of the housing in position immediately behind the screen I46. The electro-optical, or photoelectric cell 244, is preferably of a self-generating type, similar in principle to the type now widely used as photometers by amateur photographers. These devices being well-known, no detailed description thereof is deemed necessary; but it suffices to note that the electric current generated by such devices vary in strict proportionality with the amount of illumination or quantum of rays to which theyare subjected.

The wall I34 of the lamp housing I30 is formed with a rearwardly extending apertured lug 246 (Figs. 4 and 8) underlying the screens I44 and I 46. The aperture in the lug is threaded to receive a pin 248 supporting a spherical element or knuckle 250, the knuckle 250 engaging the plunger 252 (Fig. 8) of a dial indicator 254 (Figs. 1 and 8). The dial indicator 254 is mounted upon an arm 256, which swivels upon the axis of a stud 258 to which the arm is secured. The stud 258 is journalled in the arm I84 carried by the auxiliary frame 98. The dial' indicator may therefore be moved from the position shown in Figures 1, 5 and 8 to a position on the opposite side of the knuckle 250 when the contactor is positioned to engage and traverse the tooth surface or profile opposite the tooth surface or profile with which it is shown to be in engagement in Figure 5. When traversing the surfaces A (Fig. 5) of the gear teeth, the contactor I22 is deflected to the left, or in the direction of the arrow B in Figure 5, by a positive condition of a tooth surface, i. e. in the direction of the arrow B when the engaged point on the tooth surface lies outside the involute curve. Thecontactor is deflected in the opposite direction by a negative condition of a tooth surface, i. e. when the engaged point on the surface A lies inside the true involute curve. The deflection of the contactor in the direction of the arrow B allows the plunger of the indicator (which is spring pressed) to move outwardly, or upwardly as seen in Figure 5; while a movement of the contactor in the opposite direction causes the indicator plunger to move in- .wardly, or downwardly as seen in Figure 5.

When the contactor engages a surface C of gear 2, the contactor is deflected to the right, or in the direction of the arrow D in Figure 5, when the engaged point on the tooth lies outside the true surface 0. By reversing the dial indicator relative to the knuckle 250, the plunger will move outwardly upon a positive condition of a tooth surface C, and will move inwardly upon a negative condition of such tooth surface. Hence, whenever the needle of the indicator moves on one side of a reference point on its cooperating scale it will indicate a positive condition of a tooth surface, and when it moves on the opposite side of this reference point it will indicate a. negative condition" of a tooth surface.

and inwardly upon a In order that the contactor I22 may be main- ..tained in engagement with the surface being tested, it is necessary that means be provided for resiliently urging the contactor in a direction opposite to the direction of deflection of the contactor under a positive condition of the tooth surface being traversed. This means comprises a sleeve 268 (Figs. 4, 5, 12, and 13) joumalled on the block or tube I24, and having oppositely disposed laterally projecting ears or lugs 262, ,to which are pivoted pins 264 and 266. The pins 264 and 266 are received at their outer ends in diametrically disposed openings 268, in opposite wall portions 222 of the forward part 202 of the housing 228. The openings 268 are defined by outwardly diverging wall surfaces permitting sliding and swinging of the pins in the openings. Coil springs 210 and 212, embracing the pins 264 and 266 respectively, are interposed between opposed wall portions 222 and the ears or lugs 262. Angularly spaced pins-214 and 216, projecting forwardly from the boss I38, are adapted to engage a radially projecting pin 218 carried by the sleeve 268 to limit the angular movement of the sleeve relative to the block or tube I24. The

sleeve 268 projects through the forward wall of the housing 280 (see Figs. 4 and 5) and forwardly of the housing carries a laterally projecting pin 288 by which the sleeve may be adjusted angularly relative to the block I24. When the sleeve 260 is in the adjusted position shown in Figure 12 the spring 218 is compressed, while spring 212 is substantially uncompressed, hence the spring 210 exerts a force tending to move the contactor to the right, or in the direction of the arrow D in Figure 5 and into engagement with a tooth surface A. When by manipulation of the pin 280 the sleeve is adjusted-angularly to the position shown in Figure 13 the spring 212 is compressed, and the spring 218 substantially uncompressed, hence spring 212 now exerts a force tending to move the contactor to the left, or in the. direction of the arrow B in Figure 5 and into engagement with a tooth surface C.

Means are provided for micro-metrically adjusting the housing 280. and hence the screen I46 relative to the screen I44. .This means comprises a rod 282 extending through opposed walls of the housing 200 and journalled in sleeves 284 and 286, secured in opposed bosses 288 formed in the housing. The sleeve 284 is secured against rotation by a screw 298, which also provides a means for clamping the rod in adjusted positions. The sleeve 286 is secured against rotation by a set screw 292. Adjusting knobs 294 are pinned to opposite ends of the rod 282, so that regardless of the angular position which the housing 208 may occupy, due to' the angular adjustment of the mounting ring I66, one of these knobs, will be availab e for manipulation. The rod 282 carries a radial pin 296 received in an arcuate slot 298 of limited extent and formed in the sleeve 284, whereby to provide means for limiting the permissible angular adjustment of the rod,282. A collar 380 is pinned to the rod 282 and is provided with a beveled cam face 382, engaging a pin 384, carried by a lug or ear 306, projecting rearwardly from the mounting ring I66. A collar 308, loose on the rod 282, engages the pin on the side opposite the collar 300, and a coil spring 3I8 embraces the rcd 282 and is interposed between the collar 388 and a washer 3 I2, which bears against the adjacent boss 288. The clamping screw 298 being released from the rod 282, the rod may be angularly adjusted to rotate the cam collar 300,

.which as it moves from the position shown in Figure 7 allows the spring 3I8 to expand, thereby shifting the housing to the left in said figure, whereby to adjust the screen I46 relative to the screen I44, and the spring in moving the housing, also moves the rod 282 and the cam collar to the left, whereby tomaintain the cam collar in engagement with the pin 384. When the rod 282 is angularly adjusted in a direction to cause a higher point of the cam surface 302 to engage the pin 304, the cam collar and rod will be moved to the right, as seen in Figure '1, hence the housing will be shifted to the right.

The housing 280 is mounted for adjustment on the centering pins I58 and I68, as previously described (see Fig. 4), and hence as one or the other of the knobs 294 is manipulated the housing swings on these centering pins. Since the screens I44 and I 46 have a common center coincident with the axis of the stud I58 and the centering pins, this angular adjustment of the housing 200 effects the angular adjustment of the screen I46 parallel to the screen I44.

The screen I46 is by this means adjusted relative to the screen I44 to one of two zero positions in which the etched, and therefore light opaque lines, of the screens are relatively disposed as diagrammatically shown in Figures 6 and 6A. When the point of the contactor I22 is first brought into engagement with a tooth surface A, the screens are adjusted to one of these zero positions, as for example to the position shown in Figure 6, so that deflection of the contactor in the direction of the arrow B, due to a positive condition of the tooth surface, will cause a decrease in the amount of illumination or quantum of rays passing through the screens, whereas deflection of the contactor in the opposite direction, due to a negative condition of the tooth surface will cause an increase in the amount of illumination or quantum of rays passing through the screens. When the contactor is first brought into engagement with an opposite tooth surface, such as the tooth surface C, the screensare adjusted to the other zero position, as for example the position shown in Figure 6A. Hence, when the contactor I22 is deflected in the direction of the arrow D, due to a positive condition of the tooth surface C, the amount of illumination or quantum of rays passing through the screens will again be decreased, whereas when the contactor moves in the opposite direction, due to a negative condition of the tooth surface C, the amount of illumination or quantum of rays passing through the screens will be again increased. Therefore, regardless of whether the tooth surface A or the tooth surface C is being traversed, a positive condition of the tooth surface will cause a decrease in the amount of light passing through the screens, while a negative condition of the tooth surface will cause an increase in the amount of light passing throughthe screens. It will be evident, however, that the tooth surface A may be traversed with the screens in the initial position shown in Figure 6A, while the tooth surface C may be traversed with the screens in the zero position shownin Figure 6, it being merely necessary that in whichever position the screens reside initially when one tooth surface is to be traversed, it must be adjusted to the opposite position when the opposite tooth surface is to be traversed.

It will be further evident that the screens need not be in -one of the particular zero positions shown when initiating a testing operation of a tooth surface, but that they may be in any relative position which allows sufficient relative movement between the screens so that the same condition of a tooth surface will not cause first a decrease in light. and then an increase as the condition becomes more accentuated.

The position responsive control means 6 may comprise any well-known position transmitting motor" or generator 3%, having a synchronizing winding or device anda pair of oppositely active main or reversing windings. The motor 3114 (see Fig. 3) is secured to a bracket 316 in turn secured to a bracket 3| 8 that is fastened as by screws 326 to the bottom of the depending section 26 of the slide l6. A gear 322 is secured to the sleeve 26 for rotation therewith, as by means of an internally threaded hub portion received on the external threads of the sleeve 26 and an externally threaded bolt or pin received by the internal threads of the sleeve. The gear 322 meshes with the gear 324 secured to a stud shaft 326 held in the bracket -3l8. The stud 326 carries a second gear 328 that meshes with a gear 33!! on the shaft of the motor 3|4.

A horizontal movement of the slide or frame 14 causes a like movement pf the attached friction bar 92, which determines the extent of angular rotation of the base cylinder or disk 36 and the gear 38 that is to be tested. Accordingly, the rotor of the position transmitting motor 3 is rotated in strict proportionality to the horizonal movement of the testing instrumentality and in strict proportionality to the rotation of the gear 38. In other words, the rotor of the transmitter motor" is moved in strict proportionality to the relativemovement between the testing instrumentallty and the surface to be tested.

The electric recorder unit 8 may be of any wellknown conventional structure embodying an amplifier, the signal input terminals of which are connected to the photo-electric cell, and the out-- put terminals of which are connected to a conventional meter having a recording scriber or pen 332 (Figs. 15 and 16). Preferably the recorder unit 8 is a Pilotel recorder marketed by a well-known manufacturer of electrical instruments. cording unit is therefore deemed unnecessary.

The paper feed drive unit 6 comprises a shaft 334 for receiving a roll 336 of recording paper. The roll is held on the shaft by a nut 338, which may be removed from the shaft to replace the exhausted roll by a new roll. For this purpose one side wall of the housing 346 for the paper feed drive unit is provided with a door 342, which may be held in position in the housing as by a plurality of latches 344 (Figs. 14 and 15).

Upon removal of the door 342 and the nut 3316 a new roll substituted therefor. The roll is driven in a rewinding direction by a disk 346, having a portion 348 mating'with the drive hub of the paper roll. The disk 346 is driven by a ratchet 356 through a pawl 352 pivotally secured as by pin 354 to the outer face of the disk '346. The ratchet 356 is secured to and driven by a pulley 356. Pulley 356 is driven through a belt formed by a continuous coil spring 356 passing about this pulley and about a pulley 366 secured to a shaft 362.

Paper is fed from the roll by a drum 364 secured to the shaft 362 and provided adjacent its opposite edges with annular series of pins 366, providing sprocket teeth 363 received in the- Further detailed description of this reto a side wall of the housing 346.

lines of edge perforations in the recording paper.

An arcuate guide 316 may extend over a portion of the circumference of the drum 364 in spaced relation thereto to prevent the paper from jumping off the sprocket teeth. From the feeding ,roll or sprocket 364 the paper passes over a plate or anvil 312 secured to the side walls of the housing 346 and extending forwardly of the front wall 314 of the housing, thereby facilitating the feeding of the paper in the inward direction, or for rewinding on the roll.

The shaft 362 is driven by a gear 316 which meshes with a gear 318 on a stud 386, secured The gear 318 also meshes with and is driven by a gear 362 on the shaft of a receiving motor 364. This motor is similar to the position transmitting motor 3M, and is similarly provided with a synchronizing winding or device, and'a pair of oppositely acting main or reversing windings. Through the connections of 'the electric control unit i6, subsequently described, the rotor of the motor 384 is driven in synchronism with the rotor of the motor 314.

Thegear 316 is journalled on the shaft 362, and is interposed between a shoulder 366 formed on the shaft, and a collar 388, which bears against the inner race of a ball bearing 366 mounted in a fixed portion of. the adjacent side wall of the housing 340. The gear 316, the shaft 362, the collar 388, and the inner race of the ball bearing 396 are releasably forced into binding engagement by a knob 392 threaded on the outer end of the shaft, so that rotation of the gear 316 causes rotation of the shaft first in one direction and then in the other as the rotor of the motor 384 rotates first in one direction and then in the other. The knob 392 is held against inadvertent movement off the end of the shaft by a cap screw 394 threaded into the end of the shaft. Upon rotation the knob 392 in a releasing direction the gear 316 is released from binding engagement with the shoulder 386 of the shaft 362, and hence the knob 392 constitutes, in effect, a manually operable element of a clutch connection between the gear and the shaft.

When the gear 316 is released from binding engagement with the shaft, it may nevertheless drive the shaft in a direction to feed the paper forwardly, i. e. off the roll. ,This is accomplished by means of a ratchet. 396 secured to the hub of the gear 316 and engaging a pawl 368 pivotally secured as by a pin 466 to the face of a disk 462 keyed to the shaft 362. When the gear 316 is driven in a clockwise direction, as seen in Fig. 15, the teeth of the ratchet engage the pawl, and through the pawland disk drive the shaft in a clockwise direction to feed the paper forwardly. However, when the gear rotates in the counter-clockwise direction, the ratchet merely idles by the pawl, and hence the shaft is not driven in this counter-clockwise direction when the gear is released from binding engagement with the shoulder 386 of the shaft. It should be here noted that the teethv of the ratchet 396 extend oppositely relative to the teeth of .the'ratchet 356, for the ratchet 356 must drive the paper roll in a direction opposite to the direction which the ratchet 396 drives the feed roll 364.

When the feed roll is driven in the clockwise direction, as seen, in Fig. 15, to feed the paper forwardly from a roll of large diameter, the roll and the pawl 352 will be driven at an angular speed less than the speed of the ratchet 358, hence the ratchet will idle by the pawl. However, when the roll becomes of relatively small diameter, the feed roll will cause the paper roll to be driven at an angular speed which is greater than the speed of the ratchet, and hence the pawl 352 will drive the ratchet, but the belt formed by continuous coil spring 358 will yield and allow one or the other of the pulleys 356 and 368 to slip relative to this drive belt. When the feed roll and the paper roll shaft 334 are driven in a counter-clockwise direction to feed the paper backwardly, or rewind it on the roll, this continuous coil spring drive belt will again yield to permit slippage of the pulley relative to the drive belt when the feed roll becomes of such relatively large diameter that it would in the absence of such slippage of the drive belt cause the paperto break.

Knobs 484 and 486 may be pinned to outwardly projecting ends of the shafts 362 and 334 respectively to provide manually operable means by which the shafts may be operated to feed the paper forwardly or backwardly.

The housing 348 for the paper feed drive unit includes a cover 488 preferably pivotally secured as at 8 to the housing 2 for the recording -unit 8; the cover having a transparent window 4, through which operation of the scriber 332 may be observed. Means are provided for raising the recording scriber or pen 332 when the cover is raised, and to lower the scriber or pen when the cover is closed. This, means comprises a Cam 6 secured to a side flange of the cover and adapted to engagea collar 4l8 carried by one of the legs of the pen-lifting lever or wire 428 which forms a part of the electric meter of the recorder unit,

to detachably receive a plug 444 attached to a 5-conductor cable 446, connected at its other end to the position transmitting motor 3 of the position responsive control means 4. The plug 444 is of standard construction, having six contacts, but one of these contacts is not used. The socket 436 receives a plug 448 attached to a 4-conductor cable 458, connected at its other end to the testing instrumentality 2.

The connections for the control unit l8 are schematically shown in Fig. 17. As shown in this figure, the wires '452 and 454 from the synchronizing winding of the position receiving motor 384 are connected to theterminals 456 and 458 of a terminal strip 468 secured to the rear face of the panel 432; The main or forward motor winding connected internally to the terminals Ml and M-2 of the motor 384 is connected by the wires 462' and 464 to the terminals 466 and 468 of the terminal strip 468, the other main or reversing winding of the motor 384, which is connected internally to motor terminals M-2 and M3, is connected by the wire 464 and the wire 418 to the terminals 468 and 412-, respectively.

The switch 438 comprises, as best shown in Fig.

19, a pair of multiple blade switches 414 and 418 manually operated by a common lever 418. The terminal 466 from the terminal M--l of motor 384 is connected by a wire 488 and the wire 482 to the movable contact blade 484 and the fixed contact blade 486. The terminal 412 from the terminal M-3 of motor 384 is connected .by the wires 488 and 498 to the movable contact blade 492 and to the fixed blade 494. The terminal 468, connected to the common terminal M2 of motor 384, is connected by the wire 496 and the wire 498 to the movable blade 588 and to the the pen of the standard meter being in two sections pivoted to each other as at 422 to permit such raising and lowering of the recording scriber or pen. A spring 424 is secured at one end to a fixed point 426 and at its other end engages one of the legs of the pen-lifting lev'er 428, so

as to normally urge this lever in an upward direction (as seen in Fig. 15), whereby to raise the recording scriber. The cam M6 in engaging the collar 8 maintains the pen-lifting lever in its lower portion, and the pen against the recording paper on the anvil 312. Accordingly, when the cover or hood is raised to permit threadingof the paper over th roll 364 and the anvil 312, the pen is in raised position to prevent damage thereto and to the paper. The arcuate guide 318 for the paper may be secured to the cover 488 and be raised therewith to facilitate placing the paper on the sprocket teeth of the roll 364. The recorder unit 8, the paper feed drive unit 6,

" and the control unit l8 may be mounted upon a common portable standard or base 428,- (Fig. 1) so that the entire recording device may be shifted from testing machine to testing machine as may be desired.

The control unit I 8 may be mounted in the lower part of the housing 348 for the paper feed fixed blade 582. The movable blade 584 is connected by the wire 586 to the contact 588 of the socket 434. The movable blade 5l8 is connected by the wire 5l2 to the contact 5I4 of the socket 434. The fixed blade 5|6 is connected to the wire 586 and thereby to the socket contact 588. The fixed blade 5l8 is connected to the wire 5|2 and thereby to the socket contact 5l4. The fixed blade 528 is connected to the movable blade 522 and by the wire 524 to the socket contact 526.

The fixed blades 528 and 538 are inter-connected,- .and connected by the wire 532 to the socket contact 534.

of the twist lock, plug-and-socket which is connected to the line L-l of the supply cord is connected by the wire 546 to the socket contact 548. The socket contacts 534 and 548 are additionally connected by the wires 558 and 552 to the terminals 456 and 458 that are connected to the motor terminals Tl and T2 for the synchronizing thereof. J

Input power terminals 554 and 556 for the amplifier of the recorder are connected by the wires 558 to the terminals of the twist lock, plugand-socket 542. Signal input terminals 568 and 562 of the amplifier of the recorder are connected by the wires 564 and 566v respectively to the contacts 568 and 518 of the socket 436. The contact 512 of the socket 436 is connected by the wire 514 to one tap 516 of an 8-volt supply source forming part of the recorder, the other tap 518 of this 8-volt supply source being connected by the wire 588'to the wiper arm 582 of an adjustable control resistor 584 operated by the knob responsive control means 4. The contact l4 of socket 434' is connected by the wire 598 of the cable 446 to the terminal M3 of the generator 3I4, which is internally connected to one end of a main or reversing winding of this generator, the other end of this reversing winding being internally connected to the terminal M-2, and the terminal M-2 being connected by the wire 688 of the cable 446 to the contact 526 of socket 434. The contact 508 of thesame socket is connected by the wire 602 of the cable 446' to the terminal Ml of the generator 3|4, this terminal being connected to one end of the other main or forward winding which at its other end is connected to the terminal M-2.

When the plug 448 is inserted in the socket 436, the socket contact 568 is connected by the wire 604 of the cable 450 to one terminal of the photo-electric cell 244. The other terminal of the photo-electric cell is connected bythe wire 606 of the cable 450 to the socket contact 518. The contact 512 of socket 436 is connected by the wire 608 of the cable 450 to one terminal of the lamp-receiving socket 232; the other terminal of this lamp-receiving socket being connected by the wire 6 I 0 of the cable 458 to the' socket contact 592.

It will therefore be apparent that when the plugs 444 and 448 are inserted in the sockets 434 and 436 respectively, and the switch 588 closed, the lamp in the socket 232 is connected to the 8-volt terminals 516 and 518 of the power supply circuit for the amplifier of the'recorder by a circuit which extends through the wire 608, the contact 512 of socket 436, the wire 514 to the terminal 516, and from the terminal 518 through the wire 588, the Wiper-arm 582, the resistor 584, the Wire 586, the switch 588, the wire 5910, the socket contact 592, and the wire 6l0. Thus, the resistor 584 adjustably controls the luminous intensity of the lamp, and determines the sensitivity of the electro-optical testing instrumentality 2, and the consequent sensitivity of the pen 332 of the recorder. Therefore, when the surface being tested is relatively large, so that minute deviations from the true tooth surface may be neglected, the sensitivity of the testing instrumentality and the recorder may be decreased. This also has the advantage, in the case of such relatively large tooth surfaces, of preventing deviations from the true tooth surface from exceeding the range of the recorder or the-meter thereof. On the other hand, when relatively small tooth surfaces are being tested, minute deviations from the true tooth surface are of generator 3.

screens I44 and I46 or -by manipulation of the adjusting means (not shown) forming a part of the standard recorder 8.

The photo-electric cell is connected to the signal input terminals 568 and 562 of the amplifier by a circuit which extends through the wire 684, the contact 568 of socket 436, the wire 564, the terminal 560, and from the terminal 582 through the wire'566, the socket contact 518, and the wire 686.

The synchronizing winding of the generator or position transmitting motor 3l4 is connected to the synchronizing winding of the position receiving motor 384 by a circuit which extends through the wire 596, the contact 534 of socket 434, the wire 558, the terminal 458, the wire 454 to the terminal T'I of the synchronizing winding in the motor 384, and from the terminal T2 through the wire 452 to terminal 456, the wire 552, the socket contact 548, and the wire 594 to the terminal T2 for the synchronizing winding in the generator 3l4. Current is applied to both of these synchronizing windings from the supply leads Ll and L2 connected to the socket contacts 534 and 548, as previously described, to which socket contacts both synchronizing wind ings are connected when the plug 444 is inserted in the socket 434.

The forward winding of the generator 3 is connected to the forward winding of the motor 384 when the switch 438 is in the forward position by a circuit which extends from the terminal M-l through the wire 602, the socket contact 508, the wire 506, the switch blades 584 and 486, the wire 480, the terminal 466, the wire 462 to the terminal M-l of motor 384, and from the terminal M2 of said motor through the wire 464, the terminal 468, the wire 496, the switch blades 500 and 520, the wire 524, the socket contact 526, and the wire 600 to the terminal M-2 The reversing winding of the generator is connected to the reversing" sition, the forward winding of the generator is connected to the reversing winding of the of considerable importance, and hence the resistor may be adjusted to increase the sensitivity of the testing instrumentality and the recorder, so that such minute deviations will cause an ap-v preciable proportionate movement of the recordingpen.

Theposition "ofthe pen transversely of the paper may be determined by the'adjustment of there'sis'tor 584', the relative adjustment of the 7s minal M-l and from the motor terminal M-2 motor by a circuit which extends from the terminal M| of thegenerator through the wire 602, the socket contact 508, the wire 586, the switch blades 5l6 and 492, the wire 490, the wire 488, the terminal 412, the wire 418 to the terminal M3 of the motor 384. The other terminal M-2 of this reversing winding of the motor is connected to the terminal M-2 of the generator by a circuit extending through the wire 464, the

terminal 468, the wire 49s, the wire 49s, t e, switch blades 502 and, 522, the wire 524, the, socket contact 526, and the wire 600. The reversing winding of the generator is now connected to the forward winding of the motor through a circuit which extends from the terminal M--3 of the generator through the wire 598, the socket contact 5, the wire 5l2, the switch blades 5|8 and 484, the wire482, the wire 480,-

- the terminal 466, the wire m to the motor terto the generator terminal M-2, as previously described. Thus, it will be seen that when the switch 438 is in one position, the position receiving motor will operate in the same direction as the position transmitting motor, or generator, and will be synchronized therewith; but with the switch 438 is in the opposite position, the position-receiving motorwill operate in the opposite direction to the position-transmitting motor or generator, and in synchronism therewith. Accordingly, when the contactor I22 traverses one tooth surface A, the record sheet will be fed outwardly as the slide frame 14 is moved to the right. The record sheet moves inwardly, or in a direction to re-wind the paper on the roll when the slide frame 14 moves to the left' to position the testing instrumentality for the testing of the next successive tooth surface. When, however, the contactor I22 traverses a tooth surface C, the switch 438 is moved to the opposite position, and accordingly movement of the slide frame I4 to the left causes an outward movement of the record sheet, while a movement of the slide to the right to re-position the testing instrumentality for testing the next successive tooth surface C causes the record sheet to be moved inwardly, or to re-wind on the roll.

Above the switch 438 the panel 432 is provided with suitable indicia, such as the arrows H2 and GM for indicating the direction of movement of the switch lever 418 in accordance with the direction of action of the slide frame 14. Thus, when the slide 14 is to be moved to the right to traverse a tooth surface A, the switch lever is moved in the direction of the arrow 6M, or to the right; while when the frame is moved to the left to traverse a tooth surface C the switch lever is moved in the direction of the arrow M2, or to the left. Since the record sheet is moved rearwardly when the slide frame moves opposite to its. direction of action, a number of record curves may be marked in parallel on the record sheet, thus resulting in a considerable saving in the amount of paper used over a substantial period of time. The position of the pen transversely of the record sheet is determined by the setting of the shiftable screen M4 relative to the screen I46, and therefore, in order to make such utilization of the record sheet by this adjustment, one or the other of the knobs 296 of the testing instrumentality 2 must be adjusted to position the screen Hi l to different initial zero positions for successive testing operations. When the switch lever 418 of the switch 438 is moved to neutral position, the position transmitting motor or generator 3M is disconnected from the position receiving motor 3M, so that the workpiece, the testing instrumentality, and the recorder, may be preliminarly adjusted for a test without causing a feeding of the record sheet, or if desired, a test of the surface to be tested may be made by the use of the indicator 2% alone. It may from time to time occur that, for one reason or another, it is not desired nor possible to mark successively produced curves transversely of the record sheet, and therefore it is desired to cause the record sheet to move outwardly when the slide frame 14 is moved in its direction of action, but to prevent inward or reverse feeding of the record sheet when the slide frame is moved in the opposite direction to re-position the testing instrumentality for traversal of another like tooth surface.

.Hence upon rotation of the manually operable knob 392 (Figs. 14 and 16), the drive gear 316 may be released from binding engagement with the shoulder 386 of the shaft 362; and when thus released the drive gear 316 can effect rotation of the shaft 362 and the paper feed drum or sprocket 364, only in the forward direction through the ratchet 396 and the pawl 398.

Figures 20 to 22 diagrammatically indicate the manner in which the electro-optical or testing instrumentality 2 and the position responsive control means 4 may be attached to a helical lead measuring machine of standard construction to determine the correctness of the helices of the helical gear.

The gear, or other work piece, to be tested, having a helical tooth or thread, is carried by a support or shaft mounted between the center 102 of tail stock 104 and the center 106 of head stock 108. The head stock 108 comprises a shaft H0 apertured to receive the center I06, and carrying a rotatably adjustable collar H2, having an axially directed drive finger H4, engageable with a radially projecting drive finger- H6 on work support 100. The shaft H0 is driven through a gear H8 secured thereto, the gear beingalso secured to a sleeve journalled on the shaft and having a radially projecting arm I22. 0n the outer end of the shaft is loosely mounted a drum 124. The arm 122 and the inner face of the drum 124 are apertured to receive a detachable plug 126 which, when in the position shown in Figure 20, connects the sleeve 120 to the drum 124, so that the drum drives the sleeve and thereby drives the gear H8 and the shaft H0. The drum 124 is driven by steel tapes 128 passing about the drum I24 and a drum 130 secured to a shaft I32. The shaft 132 is driven by a drum 134 secured to the shaft. A gear I36 is loosely mounted on the shaft 132 and meshes with the gear H8, the gear 136 having an opening 138 and the drum having an opening "0 to receive the plug 126 by which the drum 134 may be connected to the gear 136, so that this drum may drive this gear.

The drum is driven by a vertical slide M2 connected to the drum by steel tapes 144. A disk 146 is mounted on a slide 142 for rotary adjustment relative to the slide, and carries a sine bar I48 and blocks 150. The blocks I50 are angularly spaced about the disk at the indicated angles to the longitudinal center line of the sine bar M8 as shown. Suitable angle indications may be inscribed on the disk between the blocks. Means not shown are provided for micrometrically effecting a rotary adjustment of the disk precisely to position the sine bar at the desired angle to the slide 142. The stop pin I52, carried by the slide in juxtaposition to the periphery of the disk M6 and the stop pin may have micrometer readings on both sides of a zero point to prove the set up.

A horizontal slide 154 carries at one end a roller 15B engaging the sine bar 148. The slide 154 is formed on its lower edge, or has secured thereto,

a rack 158 engageable with a gear 160 on a shaft matically indicated, by the bar 168 to a horizontally slidable test instrument support or frame "0. The electro-optical surfacetesting instrumentality 2 is mounted upon a casting I12, mounted-on-the frame 110 for sllde'adjustment transverse to the path of the movement of the frame 110 and toward and from the axis of the centers I02 and I06. Adjustment of this support casting I12 is effected by means of a knob 114 secured at the outer end of a shaft 116 journalled in the casting, and carrying at its; inner end a gear 118 meshing with a rack I80 secured to the slide frame "0. Locking of the support casting in adjusted position is effected by one or more clamping screws I82.

The lower part "8 of the supporting ring In of the testing instrumentality 2 is mounted upon, or formed integrally with an upwardly and forwardly projecting arm I84 of the support casting 112. As shown in Fig. 20, the mounting ring I66 of the testing instrumentality is angularly adjusted to position the common axis of the centers I58 and I60 at the proper helix angle for the gear to be tested, the axis of the contactor I22 intersecting the axis of the gear or work piece; or in other words, intersecting the common axis of the centers I02 and I06 at right angles there- The bracket 3I8, which supports the position transmitting motor or generator 3% of the position responsive control means 4, is secured to any convenient part of the frame of the machine, so that the gear 322, which drives this generator 3I4, meshes with the rack I58 of the slide I54. The testing instrument 2, and the position responsive control means 4 are of course provided with the connecting cables 450 and 406, as shown in Figs. 1 and 18, which cables carry the plugs 448 and 444 respectively for connecting the test-' ing instrumentality and the position responsive control means to the control unit III for the paper feed drive unit 6 and the recorder 8, as previously described.

In effecting a testing operation, the sine bar I48 is first adjusted to the angle required by the lead of a helical tooth or surface being tested. As shown in exaggerated form in Fig. 23, the lead of a helical surface or tooth is the axial distance between corresponding points on the pitch cylinder, through which distance a point must travel axially of the cylinder to generate the helix or the particularhelix angle. Therefore, when the sine bar I48 has been adjusted to.the proper lead, rotation of the hand wheel I64 causes the testing instrumentality 2 and the work piece to be given a relative proportionate rotation and translation describing the true helical surface for the gear or tooth being tested.

A positive" or negative condition of a tooth 'Surface will cause a deflection of the contactor I22 which, as previously described, will control the movement of a marking pen; the magnitude of movement of the marking pen being in exact proportion to the extent of deflection of the contactor, and the record sheet under the control of the position responsive means 4 will be fed past the marking pen in synchronism with the relative movement of translation between the work piece and the testing instrumentality.

If the sine bar I48 is in a more horizontal position, the hand wheel I64 is pulled outwardly so that the slide 154 is driven thereby; but when the sine bar stands in a more vertical position, the hand wheel is pushed inwardly to effect a driving connection to the vertical slide I42. When the slide I54 is the primary mover, the slide I52 is driven thereby through the sine bar I48; but when the slide I42 is the prime mover the sine bar drives the slide I54.

ings I38 and I40 of the gear I36 and drum I34 so that the shaft H0 is driven through the step-up gears I36 and H8.

For testing the flatness of a surface, the arrangement shown in Figs. 24 to 26 may be employed. As shown in these figures, an electrooptical testing instrumentality 800 comprises an electro-optical or photoelectric cell 802 and a ray source or lamp 804, between which is interposed a stationary screen, grid or grating 806, and a cooperating shiftable screen, grid or grating 808. The photo-electric cell, the lamp, and the screens, are mounted in housing 8I0 which in turn is mounted for rotary adjustment on a vertically adjustable sleeve or the like 8 I 2 mounted on a rod 8I3 secured to a base casting or support 8I4. The housing is held in each angular position of adjustment as by a screw BIG, and the sleeve 8I2 or the like is held in its vertically adjusted position by a screw 8I8 or the like.

Screens 806 and 808 are preferably of glass, etched or otherwise marked with horizontally extending series of spaced lines 820, preferably of the same width and spacing as in the case of the screens I44 and I46. The stationary screen 806 is mounted in a suitable frame 822, fastened in any convenient manner to the housing 800, the cell 802 being bolted to this frame 822. The shiftable screen 808 is mounted in a frame 824. The frame 822 is provided with a peripheral flange 826 encircling the frame 824. Spring strips 828 above and below the frame 824 are secured to portions of the upper and lower edges of the frame 822 and to upper and lower corners of the flange 826 of the frame 824. The spring strips 828 are calibrated so as to return the screens to the zero position or setting shown in Fig. 26 when an operating force is removed.

Shifting or deflection of the screen 808 is caused by a pin 830 screw-threaded into the lower portion of the frame 824 and having a pointed end 832 for engaging the surface of a work piece 834 to be tested, the pin 838 passing through an opening in the bottom of the housing.

The work piece 834 may be supported by any convenient work holder on a table or slide 836. the slide 836 being rectilinearly shiftable along a path parallel to the plane of the screens. The slide 836 is mountedupon slide frame 838, which is movable along a rectilinear path transverse to the plane of the screens. The table 836 carries a rack 840, with which meshes a gear 842 driven by a gear 844. The gear 844 is operated by a hand wheel 846. Thus the hand wheel 846 causes a rectilinear movement of the slide 836. The gears 842 and 844 and the shaft carrying the gear 844 and the hand wheel 846 are mounted upon a bracket 848 secured to the slide frame 838. The slide 838 also carriesa rack bar 850 driven by a gear 852 on a shaft 854, the shaft 854 also carrying a gear 856, meshing with a gear 858, driven by a hand wheel 860. The gears 852, 856, and 858 the shaft 854 and the hand wheel shaft are mounted in any convenient manner upon the base casting or support 8. Thus it will be seen that by manipulation of the hand wheel 868 the slide frame 838 is moved to shift the work piece transversely to the plane of the screens. The position transmitting motor 861 may be connected to the slides 836 and 838 through a suitable summation mechanism including a difierential gearing having the driving gears 863 and 865 connected to the slides through double ball clutch couplings or transmissions 861 and 869 insuring rotation of each of the gears 863 and 885 in the same direction independentof the direction of movement of the slides. The differential gear 8' drives the motor 86L It will be apparent that by selective or simultaneous manipulation of the hand wheels 8415 and 860, the work piece may be shifted relative to the pin or contactor 830 along any given straight line path, as indicated by the arrows 862 in Figs. 27 to 29, or may be shifted in straight line paths of such small increments as to approach a curved path. Thus it will be seen that the work piece may be tested for the flatness of its surfacealong a line extending parallel to the screens as indicated in Fig. 27, transversely to the screens, as indicated in Fig. 28, or diagonally, as shown in Fig. 29. To indicate the entire flatness of the surface/it will be best tested by the diagonal'traversal of the surface of the work piece. However, where the surface of the work piece is curved in one plane, but flat in another, the flatness of the surface in this other plane may be determined by a longitudinal or transverse traversal of the surface of the work piece as indicated in Fig. 27 or Fig. 28.

Thus it will be seen that applicant has provided a gear testing device and recorder providing means by which the data taken may be recorded at a point remote from the testing machine; means by which a single recordermay be used with any number of standard testing machines equipped with universal recorder attachments; means for electrically controlling the feeder movement of a record sheet so that the record sheet is moved in synchronism with a testing instrumentality; means for controlling the direction of the movement of the record sheet so that the record sheet may be moved in one direction, even though the direction of movement of the testing instrumentality be reversed; recorder attachments which may be used with a large number of standard surface testing machines diifering radically in construction; an electro-optical testing instrumentality responsive to deviations in the surface of an object from a desired shape in combination with electrical means responsive to a relative movement between the object and the testing instrumentality for operating a record sheet in synchronism with such relative movement, the record sheet being marked or inscribed by means controlled by the testing instrumentality; and an electro-optical surface testing instrumentality, capable of umversal adjustment to test surfaces of any desired configuration.

Changes may be made in the form, construction and arrangement of the parts without departing from the spirit of the invention or sacr ficing any of its advantages, and the right 18 hereby reserved to make all such changes as fairly fall within the scope of the following claims.

I claim: to t t and recorder 1. In a surface con ur es er means for supporting work pieces having surfaces to be tested which may extend in different'direc tions, 9. testing instrumentality including a member adapted to engage the surfaces to be tested, means for relatively moving the work piece and the testing instrumentality to cause the surface engaging member to traverse said surfaces in a forward direction of action in accordance with the direction of extension of said surfaces and reversely, a recorder having a marking member operatively controlled by said testing instrumentality, means for feeding the record sheet past the marking member in synchronism with the relative movement of the testing instrumentality and the work piece and control means for causing the record sheet to move in the same direction past the marking member during the traversal of the surfaces in a forward direction of action and to move reversely past the marking member as the testing instrumentality traverses the surfaces in a direction opposite to the direction of action.

2. In a surface tester and recorder, means for supporting a work piece the surface of which is to be tested, a testing instrumentality including a member adapted to engage the surface to be tested, means for relatively moving the work piece and the testing instrumentality to cause the surface engaging member to traverse said surface, a recorder having a marking member operatively controlled by said testing instrumentality and means for feeding a record sheet past said marking member, said feeding means comprising a synchronous drive motor, and a synchronous generator actuated by said moving means and connected to said drive motor to synchronize the movement of the record sheet with the relative movement of the testing instrumentality and the work piece.

3. In a surface tester and recorder, means for supporting a work piece the surface of which is to be tested, a testing instrumentality including a member adapted to engage the surface to be tested, means for relatively moving the work piece and the testing instrumentality to cause the surface engaging member to traverse said surface, a recorder having a marking member operatively controlled by said testing instrumentality and means for feeding a record sheet past said marking member, an electric transmitter actuated by said moving means, an electric receiver synchronized with the transmitter for driving the sheet feeding means to synchronize the movement of the record sheet with the relative movement of the testing instrumentality and the work piece.

4. In a surface tester and recorder, means for supporting a work piece the surface of which is to be tested, a testing instrumentality including a member adapted to engage the surface to be tested, means for relatively moving the work piece and the testing instrumentality forwardly and backwardly to cause the surface engaging member to traverse said surface, a recorder having a marking member operatively controlled by said testing instrumentality and means for feeding a record sheet past said marking member, synchronous driving means operatively controlled by said moving means and operatively connected to said sheet feeding means for feeding the record sheet forwardly and backwardly in synchronism with the forward and backward relative movement of the testing instrumentality and the work piece.

5. In a surface tester and recorder, means for supporting a work piece the surface of which is to be tested, a testing instrumentality including 

